1. Field of the Invention
This invention relates to the treatment of gases and more particularly it concerns an improved air scrubbing device.
2. Description of the Prior Art
U.S. Pat. No. 2,032,404 and No. 2,337,983, both to E. F. Fisher, relate to air cleaning devices wherein air to be cleaned is drawn into and through a conduit by the action of water or other liquid sprayed into the conduit. Foreign particles suspended in the air, e.g. paint from spray guns, are drawn into the conduit along with the surrounding air; and these particles are caught on the sprayed liquid. In both these Fisher patents the conduit is vertical and the liquid spray is directed downwardly into a sump. The foreign particles are carried into the sump by the downward spray. Thereafter the foreign particles are supposed to stratify in the sump, i.e. they should either sink or float according to their specific gravity; and then they are removed from the spray liquid by means of baffles or by skimming.
The devices shown in the above described Fisher patents would result in high turbulence due to the forcible impingement of the liquid sprays upon the liquid in the sump. This turbulence causes considerable frothing and foaming and hinders stratification in the sump. Also the Fisher devices are not capable of maintaining the floating material urged over to one side of the sump for convenient removal.
U.S. Pat. No. 1,222,541 to B. C. Donham relates to an air washer for cleaning foreign particles from compressed air. This air washer comprises a conduit through which the air passes and nozzles positioned at one end to spray a liquid along the length of the conduit. This tends to drive the air forwardly through the conduit while at the same time foreign particles in the air are caught up on the liquid spray within the conduit. The liquid is then separated from the accompanying air by means of eliminator plates located toward the downstream end of the device. The liquid flows down the plates and into a sump located below the conduit.
The device shown in the Donham patent would be unsatisfactory for cleaning air of adhesive type particles, such as paint, since materials of this nature would start to build up on the eliminator plates from the lower ends thereof. Also that device does not have an open sump of sufficiently large surface to allow stratification of the foreign material in the recovered liquid.
U.S. Pat. No. 3,807,145 to Engalitcheff et al shows a fluid treatment apparatus whose overall structure is similar to that of its present invention. In the Engalitcheff et al device, water sprays are directed into a conduit to impinge on mist eliminator strips. It has been discovered that the device of the Engalitcheff et al patent is capable of effectively extracting foreign particles from the air because of the intimate contact of air and water; and the present invention provides improvements which permit effective recovery and separation of these foreign materials from the sprayed liquid in an Engalitcheff et al type device.